Collins described Romney, who is reportedly under consideration for the secretary of state opening in the Trump cabinet, as a “self-serving egomaniac.”

“What do I know about Mitt Romney?” Collins said. “Well, I know that he is a self-serving egomaniac, who puts himself first, who has a chip on his shoulder and thinks he should be president of the United States. I mean, there is no love lost between me and Mitt Romney. I’ve called him a loser for the last six months.”

Collins went on to add he would leave it up to Trump to make a determination on should serve in his cabinet, but warned Romney was a “lone wolf” and may not take Trump’s direction as the nation’s top diplomat.